Abstract
Treatment of the thyroid of rats with 50-5000 r. doses of X-rays produces no change in their oxygen consumption, nor in the histological appearance of the glands in mature male rats, young growing rats, and mature animals in which the gland had been rendered hyperplastic by oral thiouracil. Doses greater than 5000 r. invariably resulted in death of the animals 9-10 days later, which could be delayed or prevented by the subcut. admn. of glucose-saline. Although death was apparently due to insufficient intake of fluid, no cause for this was found.